Stopcocks are used in a variety of fluid flow handling systems as a convenient valve for opening or closing fluid conduits and selecting between multiple fluid conduits as to which fluid conduits are open and which fluid conduits are closed. One application for such stopcocks is in the medical field where patients have medicaments infused thereinto from various different sources and medical tubing supplying various different fluids and other medicament sources are routed to stopcocks at strategic locations for medical personnel to select fluid flow from various sources to various destinations.
Two such stopcocks are described in detail in U.S. Pat. No. 8,584,701 and U.S. Published Patent Application No. 2015/0129061, both incorporated herein by reference in their entireties. Such stopcocks generally include two parts which rotate relative to each other including a housing and an insert. The housing has a plurality of ports at a periphery thereof which can each be connected to medical tubing or some other fluid vessel. The ports lead to a central hub within the housing. The insert is coupled to the housing in a manner which allows the insert to rotate relative to the housing. The insert includes a manifold shaft which fits within a hollow core of the hub.
The manifold shaft has flow pathways therein which terminate at openings in the surface of the manifold shaft. When the insert is rotated to appropriate positions, the openings on the surface of the manifold shaft become aligned or misaligned with various different ports of the hub of the housing, so that fluid flow is allowed or impeded, depending on the orientation of the insert relative to the housing. Typically, a knob is provided on the insert to assist in rotating the insert. In some embodiments, indicator plates are provided which can be selectively alignable along with the openings in the manifold shaft relative to the ports, so that the indicator plate provides a visual indication as to which ports of the stopcock are open and which ports of the stopcock are closed.
It is important that a user have high confidence that the stopcock is properly oriented, such as to avoid medication errors when the stopcock is used in a medical environment. The potential exists for a user to not exactly align the ports of the housing with the openings in the manifold shaft, with such misalignment providing the potential for improper operation of the stopcock or leakage of the stopcock. Furthermore, there is the potential even when the stopcock has been appropriately positioned, for the stopcock to be inadvertently bumped out of a proper position into an improper position. Often medical practitioners that use stopcocks purposefully attempt to position the stopcocks into a malaligned configuration with the knob between ports (or otherwise malaligned) and presumes that all of the ports are closed (“off”). However, if the malalignment is not set exactly right there is risk that small amounts of medication will flow through the stopcock unrecognized. This can lead to medication errors or unwanted medication administration.
Accordingly, a need exists for stopcocks which can hold a proper position once properly selected and which encourage the stopcock towards discrete positions which are appropriate for allowing or preventing flow therethrough, rather than allowing any random position of the insert relative to the housing. A need also exists for stopcocks which can prevent leakage while still providing confidence that the stopcock is initially in its proper selected position and that it will maintain that proper position even if jostled or bumped. A need also exists for a stopcock that allows definitive positioning between the insert and the housing thereof, such that in at least one position none of the ports communicate and all of the ports are closed (“off”).